Anyone know what that rubber strip hanging off the sidestand is actually for?

Mine has been hanging off for a while and broke off when i put the side stand today but have no idea what it is actually for. Is it worth replacing?
The haynes manual says it should be replaced once it has worn out past the wear mark but why?

Mine seem to just sort of hang there and not do anything so far as i can see?

I think it's so it can 'flip' up if you forget to put it up! Instead of jabbing in the ground and throwing you off!

Reason the RVF doesnt have one - the RVF has a sidestaind cut out switch